Can covers



March 8, 1932. J. M. YOUNG 1,848,290

PROCESS OF' TREATINGKCQN COVERS I Filed Aug. 25. 1925 2 sheets-sheep 1 F I LINE 9F BEND VERTICAL CAN END WELL mum. F'L/INGE gm I? I ATTORNEY March 8, 1932; J. M. YOUNG 1,848,290

PROCESS OF TREATING CAN COVERS .Filed Aug. 25, 1925 2 Sheets-Sheet 2 ATTORNEYS Patented 1932 nun-m srA-Tss PATENT OFF-ICE.

:omnl. YOUNG, or nnooxmm, new roan,- assronora 'ro mamas can commit,

, or new roan. 1r. Y, a conromrron or new man! unease or'ranarme can covnas.

Application fled August 25, 1925; Serial No. 62,875.

My invention relates to a process of preparing can covers and ends to enable the same to withstand the attacks ofacid'contents ofcontainers to which they are applied.

5 In drawing can ends, bottoms and covers,

in accordance with current practice, to provide an attaching (flange and to render the covers rigid, abrasions and fractures of the tin coating are uently caused, particularly at the line of hen at the base of a deep drawn wall, such as is usuall provided in thebody of the cover, inward y from the attaching llange' This exposesthe iron base of the .cover, which is then, rapidly attacked by the chemical action of food acids and the like,

resulting in minute perforations, this action being known as pin holing. Ordinarily,

. recoating this particular area of the cover is sufiicient to preventthis result, and the object of my invention is to rovide a process for locally retinning only t e particular portionof the cover which has been abraded or extent as to require a fractured to such new coat 1 Other ob ects and advantages of the invention will be ap arent as it is better understood from the ollowing description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereo J Referring to the drawings,

Figure 1 is. a perspectiveview of a can cover or end treated according to the process of my invention;

Figs. 2 and 3 are fragments thereof, showing, respectively, the condition before and after the recoating operation; and

Fig. 4 is a sectional view of a die mecha nism suitable for the practice of the invention. Y On said drawings, I have shown, for illus- I trative purposes only, a can end 11, of theusual form, having" an outer, inverted channel flange 12, formed by the well known drawing operation. A relatively deep wall 13 is formed at the inner side of the chan nel 12 and, inasmuch as the drawing of, said wall subjects the metal to avery severe strain,

- the tin'coating may be fractured in this operation, as shown at 14 in Fig.2, thereby exposing theblack metal which, when attacked by .the acid contents of the container,

may have pin holes formed therein, resulting in deterioration of the -contents. I,therefore, provide for recoating the portion of thecover on both sides, of the line of bend 15 at the base of said wall 13. Itwill be obvious that this may be accomplished by apparatus of various types and I have shown prises a disk 18, having a hub portion 19 slidably mounted upon a fixed stud 21 secured in the bottom 9f the receptacle, or tank 16. Aring 22, of rubberor the like, is carried upon the top of said disk and a similar ring 23 is carried by an annulus 24, secured by screws 25 to the disk 18, said ring 23 and annulus 24 being suitably spaced from the disk 18 and ring 22 to exposemerely that portion of the can cover to which it is desired to apply the tin coating. Said support is normally held in raised position f by means of a spring 26, surrounding the stud 21. A plunger 27, securedto a vertical rod 28, is adapted to be moved downwardly to clamp the can end against the rings 22 and 23, the latter of which is cut out at 29 to receive the outer flange of the can cover, further downward movement of said plunger moving the support and can cover downwardly, immersing the same in the liquid 17 and causing a coating. indicated by the reference character 31 in Figs. land 30f thedraw- 'ings, to be applied to the area immediately adjacent and at the line of bend 15 at the base of the vertical wall 13 of said can cover.

I use the words cover and end herein withoutintending' an -.distinction,the' bot;

ton end being ofteni entical; in construction Withv the, top end or cover.

I It is thought that the" invention and many of its attendant advantages will be understood from the foregoing description, and

it will be apparent that various changes may be made in .the'form, construction and arrangement of the parts, without departing from the spirit an scope of the invention,

.or sacrificing all of its material advantages,

2. The process of preparing drawn can ends, made of tin plate, to enable the same to withstand the chemical action of acid contents of the cans of which saidcan ends are parts, which consists in excluding the electrolyte from the main portions of the can end and locally retinning a restricted area at theline of bend of a deep drawn wall provided in the body of the end. I

3. The process of preparin drawn can ends, made of tin plate, to enab e the same to withstand the chemical action of acid contents of the cans to which they are applied, which consists in supportin an end with only a drawn portion thereof exposed and the other portions covered so as to exclude the electrolyte, and immersing the drawn portion in an end when the latter is in place and having a limited annular space through which electrolyte may contact with the can end surface at its shoulder.

7. The method of making can-ends, drawn from tin plate, resistant to pin-holding by oxygen and the can-contents, which consists in applying additional tin on the parts of the can ends where the original tin-coating has been removed or thinne by the drawing op eration. I

Joann. YOUNG.

electrolytic bath to retin the drawn portion,

and then leaving said retinning permanently on said drawn portion of the can ends.

4. The process of preparing drawn can ends, made of tin plate, to enable the same to withstand the chemical action of acid contents .of the cans to which they'are applied,

only. 5. The process of preparing drawn canwhich -consists in supporting a can end, cov ered and with a restricted area about the line of bend at the base of a deep drawn wall in the body of said end exposed to the electrolyte, and immersing the restricted area in' an electrolytic bath to retintlie exposed portion ends, made of tinplate, to enable the same withstand the chemical action of acid contents of the cans to which they are-applied, which consists -in supporting a can end with ares tricted area about the line of bend at the base ofa deep drawn wall in thebody of sad end exposed to the electrolyte, and applyin a tin coatingto the exposed portion only.

6. In an apparzttusim r'etimii'ng limited parts'of drawn can ends, the combination of- '7 an electrolytic bath receptacle, and a can end holder movable up and down in said recepta 010, said holder covering both sides of thecan 

